private void App_OnStartup(object sender, StartupEventArgs e) { var splash = new SplashScreenWindow(); splash.Show(); ServiceProvider = IOCReplacer.Create(sc => { sc.AddSingleton(this); }); var window = ServiceProvider.GetRequiredService <Views.MainWindow>(); window?.Show(); splash.Init(ServiceProvider.GetRequiredService <IAppService>()); splash.Hide(); }